/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package cn.edu.thu.laud.utils.serde;

import java.util.Date;

import org.datanucleus.store.types.ObjectStringConverter;

/**
 * Converts all dates to a range scannable key
 * @author zhuoan
 *
 */
public class DateStringConverter implements ObjectStringConverter {

	
	                                                                                                                                                                                                   	
	/* (non-Javadoc)
	 * @see org.datanucleus.store.types.ObjectStringConverter#toObject(java.lang.String)
	 */
	@Override
	public Object toObject(String str) {
		
		if(str == null || str.length() == 0){
			return null;
		}
		
		long epoch = Long.valueOf(str);
		
		return new Date(epoch);
		
	}

	/* (non-Javadoc)
	 * @see org.datanucleus.store.types.ObjectStringConverter#toString(java.lang.Object)
	 */
	@Override
	public String toString(Object obj) {
		
		if(!(obj instanceof Date)){
			return null;
		}
		
		return String.valueOf(((Date)obj).getTime());
	}

}
